Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Greece; Oncology Department, P & A Kyriakou Children's Hospital, Athens, Greece.

2

Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Greece.

3

Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Greece; Hematology-Oncology Unit, 2nd Pediatric Department, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece.

Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Greece; Clinical Epidemiology Unit, Department of Medicine, Karolinska Institute, Stockholm, Sweden. Electronic address: epetrid@med.uoa.gr.

Abstract

BACKGROUND:

Despite advances in the management of nephroblastoma (Wilms' tumor, WT), the etiology of the tumor remains obscure. We aimed to compare nephroblastoma incidence rates and time trends among children (0-14 years) in 12 Southern and Eastern European (SEE) countries and the Surveillance, Epidemiology, and End Results Program (SEER), USA, in relation to the human development index (HDI).

METHODS:

In total 1776 WT cases were recorded in 13 SEE collaborating registries (circa 1990-2016), whereas data on 2260 cases (1990-2012) were extracted from the SEER database. Age-standardized incidence rates (AIRs) were calculated and correlated with HDI, whereas temporal trends were evaluated using Poisson regression and Joinpoint analyses.

RESULTS:

The overall SEE AIR (9.2/106) was marginally higher than that of the SEER (8.3/106), whereas significant differences were noted among the 13 SEE registries which comprised mainly Caucasian populations. A statistically significant temporal increase in incidence was noted only in Belarus. Most cases (∼75%) were diagnosed before the fifth year of life, with rates steadily declining thereafter; median age at diagnosis was similar in SEE countries and SEER. A slight male preponderance in the first year of life (male:female = 1.1) was followed by a female preponderance in the older age groups (male:female = 0.7). Lastly, a statistically significant positive association between higher HDI and increasing nephroblastoma incidence was noted (regression coefficient: +3.25, 95%CI: +1.35, +5.15).

CONCLUSIONS:

Variations in incidence and time trends across the examined registries, changing male-to-female patterns with advancement in age, and positive associations with the HDI imply a plausible role for environmental and genetic factors in disease etiology, and these need to be explored further.